This invention relates to the field of release mechanisms. More particularly, the invention is directed toward an apparatus for unlatching lens covers, gimbols, instrumentation covers, etc., on orbiting telescopes, optical instrumentation or other complex and highly sensitive space instrumentation packages, where functional reliability is of paramount concern and contamination must be virtually eliminated.
In space exploration, certain types of orbital instrumentation packages are employed that necessitate pin pulling release functions. The devices currently known in the art capable of performing the required pin pulling release functions are either bulky, heavy, expensive and lack full redundancy (in case of electrically operated solenoid devices) or in the case of pyrotechnic pin pullers, exhibit outgassing and condensation contamination that have the potential for compromising test and research data. Along with the problem of contamination, many current art devices exhibit unacceptab1y high shock levels upon release. Lower release shock is particularly needed in performing release functions on orbital telescopes and other optic research projects where the instrumentation is especially susceptible to shock damage.
A pyrotechnic detent minimizes size, weight and expense and has the added desired features of low initiation power requirements, high reliability and relatively low shock. A need exists in the field of orbital research for a device that preserves the economies enumerated while eliminating the corollary problem of release actuator contamination. It is also mandatory that functional reliability not be sacrificed in meeting this need, but conversely, improved reliability is requisite to preclude the necessity of aborting a long-term, complex and expensive space research project for want of opening an equipment access door.
A Halogen Occultation Experiment (HALOE) instrument is currently being developed as part of a National Aeronautics and Space Administration ongoing research program. HALOE will provide measurement technology for long duration monitoring of the stratospheric environment. Objectives include improved understanding of stratospheric ozone depletion and study of key chlorofluoromethane (CFM) impact on ozone and interactions with ClO.sub.x, NO.sub.x and HO.sub.x chemistry. HALOE uses four gas filter correlation channels with thermal electric cooled IR detectors and four broadband radiometer channels with thermistor heliometers to measure eight stratospheric constituents of interest by the absorption of solar energy during sunrise and sunset events. Vertical profiles are obtained by tracking the solar disc during occultation.
After an appropriate period on-orbit to facilitate spacecraft outgassing a telescope door which prevented opcical contamination must be opened. Because of the extreme delicacy of the instrument and its heightened sensitivity to contamination, a system for effecting the telescope cover mechanical release function that is small, lightweight, contamination-free and has full redundancy of operation to ensure performance is desired.
Accordingly, it is an object of this invention to provide a release system that is contamination free when operated.
Another object of the present invention is to provide a mechanical release system that is redundant in all phases of operation (electrically, pyrotechnically and mechanically) to ensure functional reliability.
Yet another object of this invention is to provide a release system that minimizes release shock by channeling the shock to rectilineal motion along the axis of a pin release mechanism.
It is also an object of the present invention to provide a release system that is longitudinally symmetrical and cannot be inadvertently installed backward.
An additional object of the present invention is to provide a highly reliable release system that is of lightweight construction, of small size, has low initiation energy requirements and performs with reduced pyro-shock effects.